The invention relates to a piercer which is capable of piercing positioning apertures for darts or pockets through a stack of cloths in one operation during a sewing process of clothes.
It is known to perform such operation by using an electric drill which is held by hand. However, such operation tends to form drilled holes in the upper surface of a table. A few instruments are commercially available which are designed to avoid such problem when set on a table. However, there has been no apparatus available on the market which determines a location to be apertured exactly and which automatically responds to the positioning operation to perform an up and down or elevating movement of an electric drill.
The invention has been developed to satisfy such need. Specifically, the invention provides a piercer comprising a frame including an upper and a lower frame section of given lengths and disposed in parallel and opposing relationship with a given difference in elevation therebetween, a channel plate extending upright from the free end of the upper frame section to a given height with a guide plate or guide rail extending along the length thereof, a slider movable up and down along the guide plate, a rotary drill secured to the slider with its drill bit directed downside, a reflector disposed slightly below the drill bit, the reflector effecting reflection of light from a lamp which is disposed on one side wall of the channel plate to project an optical point mark to a location which is vertically and directly below the tip of the drill bit, the reflector being disposed for movement away from its normal position during the upward or downward movement of the slider, and an anti-deflection holder plate located slightly above the tip of the drill bit, the anti-deflection holder plate moving down together with the rotary drill and remaining on an uppermost one of the cloths during the piercing operation of the drill bit through the cloths and moving upward during the upward movement of the rotary drill.